When a layer of material, including in some cases an epitaxial layer, is grown upon a substrate, it is sometimes desirable to be able to remove the film intact from the substrate. This can provide a free-standing layer or film of the material that has been grown, and it can make the substrate available for use again as a growth substrate for another layer of the material. For semiconductor and other potentially light-emitting materials that are to be employed in light-emitting devices, the degree to which the internally generated light is emitted for use external to the device can be greatly enhanced by having a textured surface for enhanced outcoupling of the light.
Numerous post-growth processing techniques have been employed to provide textured surfaces that couple light more efficiently out of a semiconductor light-emitting device, such as light-emitting diodes and a laser diodes. Such post-growth processes add to the complexity of device fabrication. Lithography followed by dry etching, wet etching, or a combination of the two are typically used for creating textured surfaces. A simpler, more direct approach would be desirable.